Transcriptional_reprogramming_from_innate_immune_functions_to_a_pro_thrombotic_signature_upon_SARS_CoV_2_sensing_by_monocytes_in_COVID_19

Alterations in the myeloid immune compartment have been observed in COVID-19, but the specific mechanisms underlying these impairments are not completely understood. Here we examined the functionality of classical CD14+ monocytes as a main myeloid cell component in well-defined cohorts of patients with mild and moderate COVID-19 during the acute phase of infection and compared them to that of healthy individuals. We found that ex vivo isolated CD14+ monocytes from mild and moderate COVID-19 patients display specific expression patterns of costimulatory and inhibitory receptors that clearly distinguish them from healthy monocytes, as well as an altered metabolic profile. In addition, decreased NFB activation in COVID-19 monocytes ex vivo is accompanied by an intact type I IFN antiviral response. Secondary pathogen sensing ex vivo led to a state of functional unresponsiveness characterized by a defect in pro-inflammatory cytokine expression, NFB-driven cytokine responses and defective type I IFN response in moderate COVID-19 monocytes, together with defects in the metabolic reprogramming that innate immune cells usually undergo upon pathogen sensing. Transcriptionally and functionally, COVID-19 monocytes switched their gene expression signature from canonical innate immune functions to a pro-thrombotic phenotype characterized by enrichment of pathways involved in hemostasis, immunothrombosis, platelet aggregation and other accessory pathways to platelet activation, accumulation and clot formation, including extracellular matrix reorganization, integrin cell surface interactions and signaling by PDGF. These results provide a potential mechanism by which innate immune dysfunction in COVID-19 may contribute to disease pathology

Type: Transcriptome Analysis
Archiver: European Genome-Phenome Archive (EGA)

1 Dataset 1 Publication

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Dataset ID	Description	Technology	Samples
EGAD00001009800	This dataset was used to compare gene expression profiles of ex vivo isolated classical CD14+ monocytes from patients with moderate COVID-19 to those of healthy individuals. Blood samples were taken from patients with moderate COVID-19 admitted to hospitals in London (Hammersmith Hospital, Charing Cross Hospital, Saint Mary’s Hospital) 3-14 days after disease onset and 0-2 days after hospitalization and positive PCR, and before study treatment initiation. Moderate patients displayed mild or moderate COVID-19 pneumonia, defined as grade 3 or 4 WHO severity. Samples were collected from March 2020 to February 2021. Healthy donors were Imperial College staff with no prior diagnosis of or recent symptoms consistent with COVID-19, and where possible, were matched in age and sex distribution with COVID-19 patients. None of the participants of this study were COVID-19 vaccinated. Peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll Hypaque (GE Healthcare) gradient centrifugation <4 hours after blood collection. CD14+ monocytes were isolated using a positive selection magnetic sorting kit (StemCell Technologies, UK) from total PBMC and stimulated with vehicle, UV-inactivated SARS-CoV-2 (CoV-2). RNA was isolated using the RNeasy Micro Plus Kit (QIAGEN) following the manufacturer’s guidelines. RNA-sequencing was performed by the Oxford Genomics Centre. PolyA-enriched strand- specific libraries were prepared using NEBNext Ultra II Directional RNA Library Prep Kits (Illumina). All samples were pooled together and 150bp PE reads were sequenced on a Novaseq 6000 system.	Illumina NovaSeq 6000	42

Publications	Citations
Transcriptional reprogramming from innate immune functions to a pro-thrombotic signature by monocytes in COVID-19. Maher AK, Burnham KL, Jones EM, Tan MMH, Saputil RC, Baillon L, Selck C, Giang N, Argüello R, Pillay C, Thorley E, Short CE, Quinlan R, Barclay WS, Cooper N, Taylor GP, Davenport EE, Dominguez-Villar M. Nat Commun 13: 2022 7947	9